   * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        :root {
            --primary: #2c3e50;
            --secondary: #3498db;
            --accent: #e74c3c;
            --light: #ecf0f1;
            --dark: #2c3e50;
            --text: #333;
            --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            --transition: all 0.3s ease;
        }
        
        body {
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            color: var(--text);
            line-height: 1.6;
        }
        
        header {
            background: var(--primary);
            color: white;
            padding: 1rem 5%;
            display: flex;
            justify-content: space-between;
            align-items: center;
            box-shadow: var(--shadow);
            position: sticky;
            top: 0;
            z-index: 100;
        }
        
        .logo {
            display: flex;
            align-items: center;
            gap: 15px;
        }
        
        .logo i {
            font-size: 2rem;
            color: var(--secondary);
        }
        
        .logo h1 {
            font-size: 1.8rem;
            font-weight: 700;
        }
        
        nav ul {
            display: flex;
            list-style: none;
            gap: 2rem;
        }
        
        nav a {
            color: white;
            text-decoration: none;
            font-weight: 600;
            padding: 0.5rem 1rem;
            border-radius: 4px;
            transition: var(--transition);
            position: relative;
        }
        
        nav a:hover {
            color: var(--secondary);
        }
        
        nav a::after {
            content: '';
            position: absolute;
            bottom: -5px;
            left: 0;
            width: 0;
            height: 3px;
            background: var(--secondary);
            transition: var(--transition);
        }
        
        nav a:hover::after {
            width: 100%;
        }
        
        .cta-button {
            background: var(--secondary);
            color: white;
            padding: 0.7rem 1.5rem;
            border-radius: 50px;
            text-decoration: none;
            font-weight: 600;
            transition: var(--transition);
            display: inline-block;
            border: 2px solid transparent;
        }
        
        .cta-button:hover {
            background: transparent;
            border-color: var(--secondary);
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
        }
        
        main {
            display: flex;
            min-height: calc(100vh - 150px);
            padding: 2rem 5%;
        }
        
        .branch {
            flex: 0 0 250px;
            background: white;
            border-radius: 10px;
            padding: 2rem 1.5rem;
            box-shadow: var(--shadow);
            margin-right: 2rem;
            height: fit-content;
        }
        
        .branch h2 {
            color: var(--primary);
            margin-bottom: 1.5rem;
            padding-bottom: 0.5rem;
            border-bottom: 2px solid var(--secondary);
        }
        
        .branch ul {
            list-style: none;
        }
        
        .branch li {
            margin-bottom: 0.8rem;
            padding: 0.8rem;
            border-radius: 5px;
            transition: var(--transition);
        }
        
        .branch li:hover {
            background: var(--light);
            transform: translateX(5px);
        }
        
        .branch li.active {
            background: var(--secondary);
            color: white;
        }
        
        .branch a {
            text-decoration: none;
            color: var(--dark);
            display: block;
            font-weight: 500;
        }
        
        .branch li.active a {
            color: white;
        }
        
        .branch i {
            margin-right: 10px;
            width: 20px;
            text-align: center;
        }
        
        .content {
            flex: 1;
            background: white;
            border-radius: 10px;
            padding: 2.5rem;
            box-shadow: var(--shadow);
        }
        
        .hero {
            background: linear-gradient(rgba(44, 62, 80, 0.8), rgba(44, 62, 80, 0.9)), url('https://images.unsplash.com/photo-1497366754035-f200968a6e72?ixlib=rb-4.0.3') center/cover;
            color: white;
            text-align: center;
            padding: 4rem 2rem;
            border-radius: 10px;
            margin-bottom: 2rem;
        }
        
        .hero h2 {
            font-size: 2.5rem;
            margin-bottom: 1rem;
        }
        
        .hero p {
            font-size: 1.2rem;
            max-width: 700px;
            margin: 0 auto 2rem;
        }
        
        .features {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 2rem;
            margin: 3rem 0;
        }
        
        .feature-card {
            background: var(--light);
            padding: 2rem;
            border-radius: 10px;
            text-align: center;
            transition: var(--transition);
        }
        
        .feature-card:hover {
            transform: translateY(-10px);
            box-shadow: var(--shadow);
        }
        
        .feature-card i {
            font-size: 3rem;
            color: var(--secondary);
            margin-bottom: 1.5rem;
        }
        
        .feature-card h3 {
            margin-bottom: 1rem;
            color: var(--primary);
        }
        
        .section-title {
            text-align: center;
            margin: 2rem 0 3rem;
            color: var(--primary);
            position: relative;
        }
        
        .section-title::after {
            content: '';
            position: absolute;
            bottom: -15px;
            left: 50%;
            transform: translateX(-50%);
            width: 80px;
            height: 4px;
            background: var(--secondary);
            border-radius: 2px;
        }
        
        .products {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 2rem;
            margin: 3rem 0;
        }
        
        .product-card {
            border: 1px solid #eee;
            border-radius: 10px;
            overflow: hidden;
            transition: var(--transition);
        }
        
        .product-card:hover {
            transform: scale(1.03);
            box-shadow: var(--shadow);
        }
        
        .product-img {
            height: 200px;
            background: linear-gradient(45deg, #3498db, #2c3e50);
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 1.5rem;
            font-weight: bold;
        }
        
        .product-info {
            padding: 1.5rem;
        }
        
        .product-info h3 {
            margin-bottom: 0.5rem;
            color: var(--primary);
        }
        
        .product-info p {
            margin-bottom: 1rem;
            color: #666;
        }
        
        .price {
            font-size: 1.5rem;
            font-weight: bold;
            color: var(--accent);
            margin-bottom: 1rem;
            display: block;
        }
        
        footer {
            background: var(--dark);
            color: white;
            padding: 3rem 5%;
        }
        
        .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 3rem;
        }
        
        .footer-section h3 {
            margin-bottom: 1.5rem;
            position: relative;
            padding-bottom: 0.5rem;
        }
        
        .footer-section h3::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 0;
            width: 50px;
            height: 2px;
            background: var(--secondary);
        }
        
        .footer-links {
            list-style: none;
        }
        
        .footer-links li {
            margin-bottom: 0.8rem;
        }
        
        .footer-links a {
            color: #ddd;
            text-decoration: none;
            transition: var(--transition);
        }
        
        .footer-links a:hover {
            color: var(--secondary);
            padding-left: 5px;
        }
        
        .contact-info {
            list-style: none;
        }
        
        .contact-info li {
            margin-bottom: 1rem;
            display: flex;
            align-items: flex-start;
            gap: 10px;
        }
        
        .contact-info i {
            color: var(--secondary);
            margin-top: 4px;
        }
        
        .social-links {
            display: flex;
            gap: 1rem;
            margin-top: 1.5rem;
        }
        
        .social-links a {
            display: flex;
            align-items: center;
            justify-content: center;
            width: 40px;
            height: 40px;
            background: rgba(255, 255, 255, 0.1);
            border-radius: 50%;
            color: white;
            transition: var(--transition);
        }
        
        .social-links a:hover {
            background: var(--secondary);
            transform: translateY(-3px);
        }
        
        .copyright {
            text-align: center;
            padding-top: 2rem;
            margin-top: 2rem;
            border-top: 1px solid rgba(255, 255, 255, 0.1);
            color: #aaa;
            font-size: 0.9rem;
        }
        
        /* 响应式设计 */
        @media (max-width: 900px) {
            main {
                flex-direction: column;
            }
            
            .branch {
                flex: 1;
                width: 100%;
                margin-right: 0;
                margin-bottom: 2rem;
            }
            
            nav ul {
                gap: 1rem;
            }
        }
        
        @media (max-width: 768px) {
            header {
                flex-direction: column;
                gap: 1rem;
                text-align: center;
            }
            
            .logo {
                justify-content: center;
            }
            
            nav ul {
                flex-wrap: wrap;
                justify-content: center;
            }
            
            .hero h2 {
                font-size: 2rem;
            }
        }
        
        @media (max-width: 480px) {
            .hero {
                padding: 2rem 1rem;
            }
            
            .hero h2 {
                font-size: 1.8rem;
            }
            
            .content {
                padding: 1.5rem;
            }
        }